A call to action is an invitation, often commercial in nature, to carry out a given task.

To encourage the user (or consumer) to carry out said task – for example, getting them to sign up to a newsletter, fill out a form or even purchase a product or service – special graphical elements and texts are designed with a view to persuading the user to complete the task in question.

"Calls to action" can take the form of buttons, adverts or landing pages, featuring short, succinct messages that lead the recipients towards what it being asked of them. Classic examples of calls to action include "Buy now", "Click here" and "Sign up now".